If you want to contribute (implement something from the current list, or
anything), contact the developer's mailing list (gnutls-dev@lists.gnupg.org),
in order to avoid having people working on the same thing. 

Current list:
+ Audit the code
* Precalculate signatures for DHE cipher suites
* Minimize footprint.
* Improve support for compression
- Add Kerberos support

(+) Means high priority 
(*) Means medium priority
(-) Means low priority (ie. nobody is interested to develop that)
